Abstract Recovering drug addicts encounter danger when faced with drug-related cues or contexts, because those situations can trigger relapse. Similarly, bouts of binge eating are often triggered by cues for food relevant rewards. Cues are especially potent triggers when individuals are in vulnerable states. These proposal aims to identify the brain states that cause vulnerability to cue-triggered 'wanting' of reward. The responsible brain mechanisms particularly involve the limbic nucleus accumbens and amygdala. Here we will study how these brain mechanisms cause excessive incentive salience ('wanting') to be attributed to particular reward cues. In experiment 1, microinjections of agonist drugs and a Fos plume mapping tool will be used to identify the neural mechanisms in nucleus accumbens and amygdala that magnify cue-triggered 'wanting'. In experiment 2, the circuit principles that join together the nucleus accumbens and amygdala into a cooperative system will be identified by manipulating the structures with multiple simultaneous microinjections. In experiment 3, prior neural sensitization and learning manipulations will help show how natural 'wanting' mechanisms are usurped by drugs and sensitization to cause an addicted reward to be 'wanted' more than other rewards. These studies will help clarify the brain and psychological mechanisms that cause addicts to excessively 'want' drug and binge eaters to excessively 'want' food rewards.